1. Field of the Invention
The present invention relates to a battery holding device.
2. Discussion of the Background
A capacitor that supplies electrical power to, for example, a motor is installed in a vehicle such as an electric vehicle (EV) or a hybrid electrical vehicle (HEV). A plurality of storage cells that are connected in series are provided in the capacitor. For the storage cells, secondary batteries, such as nickel metal hydride batteries or lithium-ion batteries, are used. The output characteristics of such secondary batteries depend upon temperature, and are reduced when the temperature is low. Therefore, when a vehicle (such as an EV or a HEV) in which a capacitor including a secondary battery is installed is used in a cold region, particularly, during the winter, a predetermined output may not be obtained because a sufficient amount of electrical power is not supplied to the motor from the capacitor.
To overcome this problem, as shown in FIG. 9, a secondary battery module discussed in Japanese Unexamined Patent Application Publication No. 2006-269426 includes a PTC heater 24′ between a division wall 15′ and an electric cell 11′ in a housing 12′ having the electric cell 11′ built therein. The PCT heater 24′ generates heat by receiving electrical power supplied from a generator or a lead storage battery, provided in an automobile, and heats air flowing into the housing 12′.
As shown in FIG. 10, Japanese Patent Application Publication (KOKAI) No. 2006-269426 discusses a secondary battery module in which a PTC heater 27 is brought into contact with an electric cell 11″ and is disposed in a recessed portion 150″ of a division wall 15″. In this secondary battery module, the PTC heater 27 is in close contact with the division wall 15″ without providing an interval therebetween. For this reason, a through hole 27a for air flow is provided in the PTC heater 27.
In a battery discussed in Japanese Patent Application Publication (KOKAI) No. 2004-063397, as shown in FIG. 11, a heater section 300 is embedded in an electrolytic layer 122 of a bipolar battery including a positive-pole active material layer 121, the electrolytic layer 122, and a negative-pole active material layer 123, which are arranged side by side in that order. The heater section 300 generates Joule heat while electrical current flows to a negative-pole external terminal 112 from a positive-pole external terminal 111 through the heater section 300. As a result, the battery is heated by the Joule heat that is internally generated.
In the secondary battery module discussed in Japanese Patent Application Publication No. 2006-269426 discussed above, the PTC heater 24′ is provided between the electric cell 11′ and the division wall 15′, and the PTC heater 27 is provided between the electric cell 11″ and the division wall 15″. In the secondary battery modules, when cooling the electric cells 11′ and 11″, cooling air is blown to a space between the division wall 15′ and the electric cell 11′ that is not occupied by the PTC heater 24′ or the through hole 27a of the PTC heater 27, respectively. However, when the number of PTC heaters is increased to increase a heating range of the batteries 11′ and 11″ by the respective PTC heaters 24′ and 27, the cooling air may not flow adequately.
Although Japanese Patent Application Publication No. 2004-063397 discussed above discusses increasing the temperature of the battery by the heater section 300, it does not discuss cooling the battery by causing cooling air to flow between a plurality of bipolar batteries.